This is my entry into the Second Summer of Math Exposition. I used to wonder about these questions ever since my first year in university, so in a sense this is a rather personal subject for me. I hope that this video reaches someone else who is also wondering about these issues.
Here's the Desmos document for visualizing the n complex roots of any complex number:
https://www.desmos.com/calculator/1v4...
Videos mentioned in order of apparition:
e to the pi i, a nontraditional take (old version)
e to the pi i, a nontraditional take (old ...
The 'Everything' Formula - Numberphile
The 'Everything' Formula - Numberphile
Winding numbers and domain coloring
Winding numbers and domain coloring
The 5 ways to visualize complex functions | Essence of complex analysis #3
The 5 ways to visualize complex functions ...
Visualizing Complex-Valued Functions
Visualizing Complex-Valued Functions
Jeff Tupper's webpage on the graph of x^x
http://www.peda.com/grafeq/gallery/ro...
A relevant Stack Exchange question and answer that touches on these ideas:
https://mathematica.stackexchange.com...
Chapters:
00:00 Intro and problem motivation
01:49 The R-to-C graph of x^a
04:37 The R-to-C graph of a^x
06:37 Rotations in complex exponentiation
07:27 The R-to-C graph of x^x
08:17 An alternative version of the graph of x^x
12:37 Recap of the various graphs of x^x
13:49 Homework
14:09 Summary and outro
Music by Vincent Rubinetti
Download the music on Bandcamp:
https://vincerubinetti.bandcamp.com/a...
Stream the music on Spotify:
https://open.spotify.com/album/1dVyjw...
This is my entry into the Second Summer of Math Exposition. I used to wonder about these questions ever since my first year in university, so in a sense this is a rather personal subject for me. I hope that this video reaches someone else who is also wondering about these issues.
Here's the Desmos document for visualizing the n complex roots of any complex number:
https://www.desmos.com/calculator/1v4...
Videos mentioned in order of apparition:
e to the pi i, a nontraditional take (old version)
e to the pi i, a nontraditional take (old ...
The 'Everything' Formula - Numberphile
The 'Everything' Formula - Numberphile
Winding numbers and domain coloring
Winding numbers and domain coloring
The 5 ways to visualize complex functions | Essence of complex analysis #3
The 5 ways to visualize complex functions ...
Visualizing Complex-Valued Functions
Visualizing Complex-Valued Functions
Jeff Tupper's webpage on the graph of x^x
http://www.peda.com/grafeq/gallery/ro...
A relevant Stack Exchange question and answer that touches on these ideas:
https://mathematica.stackexchange.com...
Chapters:
00:00 Intro and problem motivation
01:49 The R-to-C graph of x^a
04:37 The R-to-C graph of a^x
06:37 Rotations in complex exponentiation
07:27 The R-to-C graph of x^x
08:17 An alternative version of the graph of x^x
12:37 Recap of the various graphs of x^x
13:49 Homework
14:09 Summary and outro
Music by Vincent Rubinetti
Download the music on Bandcamp:
https://vincerubinetti.bandcamp.com/a...
Stream the music on Spotify:
https://open.spotify.com/album/1dVyjw...
Q. How did you do the 3D animations?
A. I programmed them in Python, using the manim library: https://www.manim.community
Q. How can I play around with these types of graphs myself?
A. Any software that can graph 3D parametric curves will do, but you do have to define the real and imaginary parts of the parametric function yourself. Here's an interactive example for x^a using GeoGebra 3D: https://www.geogebra.org/m/wtqwhswu
Q. Isn't x^2.4 just the 5th-degree root of x^12? (and thus just a negative number for negative x?)
A. That is one possible way to interpret it, yes. There are other just-as-valid interpretations. This is what I wanted you to think about with the suggested exercise at 13:50. When the exponent a in x^a can be written as a fraction with an odd base (which is the case for 2.4 = 12/5) then one of the many values of x^a will be a real number, even for negative x. Which one of the multiple values to pick from can be subject to debate, and you can see that in the showcase starting at 00:23 only one of the three graphing tools that we tested (Desmos) chooses this interpretation of always assigning a real value to x^a when possible.
Q. So you are defining x^a by using e^something-else? Isn't that a circular definition?
A. No. The function e^x or exp(x) is not understood to be an exponentiation, but rather a function defined by its series expansion (this expansion can be seen at 07:07).
Q. Where do all of these definitions come from anyway?
A. That's a great question, hopefully for another video.